With the development of economy and society, there is ever-rising demand for noble metals. Noble metals, especially platinum group metals, are more and more widely applied in various fields such as petrochemical industry, exhaust gas purification, electronics and the like. There are rare reserves of platinum group metals in the crust, but in some noble metals-containing waste resources, such as discarded electronic components, etc., there contain a substantial content of noble metals of platinum and palladium. Recovery of noble metals of platinum and palladium from secondary resources may make up part of the shortage of supply. With the development of various fields, the secondary resources producing noble metals of platinum and palladium are also increasing. Therefore, recycling of waste containing noble metals of platinum and palladium into resources has become a major subject along with the development of our society and economy.
There are many methods for enriching and recovering noble metals, the traditional separation and extraction process for platinum group is mainly based on precipitation, which has the disadvantages such as tedious process, low yield, high cost and complicated operation. Since the process of solvent extraction and separation process showed its superiority, application of the process for extracting and purifying platinum group metals has attracted great attention. Solvent extraction technology, which has the advantages such as simple process, good separation effect, high yield of noble metals, safe production operations, high suitability and flexibility for various materials, large processing capacity, easy implementation of automation and the like, has been regarded by domestic and international scholars as a high and new technology for separating and extracting platinum group metals.
However, in the process of solvent extraction, due to the complexity of the components contained in the waste of resources, separation and enrichment of noble metals from base metal have always been a relatively tedious process. The presence of base metals often affects extraction and recovery of noble metals, resulting in shortcomings including complex process of recovery, increased energy consumption, environmental pollution, as well as low cost efficiency and the like.